1. Field of the Invention
The present invention relates to a semiconductor device fabricating method and fabricating apparatus. In particular, the present invention relates to a semiconductor device fabricating method and fabricating apparatus that include a process of picking-up and conveying a semiconductor chip, and flip-chip connecting obverse electrodes of the semiconductor chip to a package substrate.
2. Description of the Related Art
Semiconductor chips that have been separated into individual chips from a wafer are picked-up one-by-one and conveyed to a bonding device. Conventionally, when carrying out bonding by flip-chip connection, a bonding device having a bonding head that is generally called a collet is used. A single suction hole that passes-through the bonding head is provided in the bonding head. The reverse (rear surface) of the semiconductor chip is attracted to the attracting surface of the bonding head by suction from this suction hole. The semiconductor chip is attracted to the bonding head, and is conveyed to a position at which bump electrodes, that are provided at the obverse of the semiconductor chip, and bump electrodes of a package substrate oppose one another. Then, the bump electrodes that oppose one another are joined together by being heated while pressure is applied, or the like.
Various modified examples have been proposed for the configurations of the attracting surface and the attracting opening of the bonding head in order for the bonding head to function as a semiconductor chip attracting device and conveying device (Japanese Patent Applications Laid-Open (JP-A) Nos. 63-29539, 7-66268). For example, JP-A No. 63-29539 proposes providing a groove at the periphery of the attracting opening, in order to facilitate canceling of the state of holding by the attraction. Further, JP-A No. 7-66268 proposes an attracting device that attracts and holds a semiconductor chip via an attracting collet that has a chip contacting portion that contacts the semiconductor chip while avoiding a contact prohibited region.
Manufacturing techniques have recently been proposed that stack semiconductor chips in plural layers, such as the chip-on-chip technique and the chip stacking technique. In these structures, in order to stack semiconductor chips, bump electrodes are provided not only at the obverse side of the semiconductor chip, but at the reverse side as well. However, a conventional bonding device does not suppose the conveying of a semiconductor chip with electrodes at both sides at which bump electrodes are formed at the obverse and the reverse. Various problems have therefore arisen.
For example, a case in which a semiconductor chip 30 with electrodes at both sides is attracted and conveyed by a bonding head 100 as shown in FIG. 10A will be described. Bump electrodes 32 are provided on the obverse side of the semiconductor chip 30, and bump electrodes 34 are provided on the reverse side. The bump electrodes 32 and the bump electrodes 34 are electrically connected by pass-through electrodes 36 that pass-through the substrate of the semiconductor chip 30.
The region where the bump electrode 34 of the reverse side of the semiconductor chip 30 is provided is, as shown by the arrow, directly sucked by an attracting opening 104 of a pass-through hole 102 provided in the bonding head 100 as shown in FIG. 10B. Further, the region where the corresponding obverse side bump electrode 32 is provided also is sucked simultaneously via the substrate.
Due to the region where the obverse side bump electrode 32 is provided being sucked, the problem arises that the bump electrode 32 does not contact the bump electrode of the package substrate, and the opposing bump electrodes are not joined together well. Further, due to the bump electrode 32 that should be joined not being joined, and the like, stress differences arise within the semiconductor chip 30, and there are cases in which the semiconductor chip 30 breaks and bonding cannot be carried out. Moreover, due to the reverse side of the semiconductor chip 30 being locally sucked by the attracting opening 104, there are also cases in which the bump electrode 34 at the reverse side deforms, or stress concentrates at the portion along the outer periphery of the attracting opening 104 and the semiconductor chip 30 breaks, and bonding cannot be carried out.
The above-described problems appear markedly in particular due to (1) the semiconductor chip being made thin to a thickness of 50 μm or the like and (2) bump electrodes being disposed not only at the chip periphery but at the chip central portion as well, and the like, that, in addition to bump electrodes being formed on the obverse and the reverse of the semiconductor chip, have accompanied the recent trend toward higher integration.